V3 spinal neurons establish a robust and balanced locomotor rhythm during walking.
A robust and well-organized rhythm is a key feature of many neuronal networks, including those that regulate essential behaviors such as circadian rhythmogenesis, breathing, and locomotion. Here we show that excitatory V3-derived neurons are necessary for a robust and organized locomotor rhythm during walking. When V3-mediated neurotransmission is selectively blocked by the expression of the tetanus toxin light chain subunit (TeNT), the regularity and robustness of the locomotor rhythm is severely perturbed. A similar degeneration in the locomotor rhythm occurs when the excitability of V3-derived neurons is reduced acutely by ligand-induced activation of the allatostatin receptor. The V3-derived neurons additionally function to balance the locomotor output between both halves of the spinal cord, thereby ensuring a symmetrical pattern of locomotor activity during walking. We propose that the V3 neurons establish a regular and balanced motor rhythm by distributing excitatory drive between both halves of the spinal cord.
Zhang
Ying
Y
Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
Narayan
Sujatha
S
Geiman
Eric
E
Lanuza
Guillermo M
GM
Velasquez
Tomoko
T
Shanks
Bayle
B
Akay
Turgay
T
Dyck
Jason
J
Pearson
Keir
K
Gosgnach
Simon
S
Fan
Chen-Ming
CM
Goulding
Martyn
M
D000200:Action Potentials / Q000235:genetics / Q000502:physiology; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000502:physiology; D007395:Interneurons / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D009043:Motor Activity / Q000235:genetics / Q000502:physiology*; D009046:Motor Neurons / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology; D004856:Postural Balance / Q000502:physiology*; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology; D013116:Spinal Cord / Q000502:physiology*; D016138:Walking / Q000502:physiology*
D051792:Basic Helix-Loop-Helix Proteins; D012097:Repressor Proteins; C491094:SIM1 protein, human